Devastated by the loss, Hugh and his Japanese wife Setsuko divorce. Severing all ties to America, Setsuko returns to Japan to live with her father, Kazuki Ono, a prominent author of mind-bending novels.
After grieving for ten years and longing for Setsuko, Hugh swims out to sea to drown himself. As he sinks, his sons appear to him, holding the last letter that he had sent to their mother, begging her forgiveness.
Abandoning his suicide, Hugh swims back to shore. The incident awakens memories that throw doubt on the accepted version of his sons' deaths. His doubts are intensified when he learns that Kazuki Ono has come to California to finish a novel called Fingal's Cave, the tale of a brash American who marries a Japanese woman against the wishes of her father, a powerful businessman with ties to the Yakuza.
Provoked by his memories and obliquely revealing passages found in Kazuki's books, Hugh begins a Quixotic journey across the California landscape, encountering numerous characters of ill-will and cross-purpose, but who inexorably lead him toward a film-industry firm called Nakamura Reality, and a labyrinth that challenges him to separate reality from fiction to find his way out... and perhaps back to his sons.